Sound amplifier



T. G. WILLIAMS .Iunem3f1930- SOUND AMPLIFIER Filed April 2, 1928 wif Patented June 3, 1930 THEOPHIL'US Gr. WILLIAMS, GF MORRISTOWN, NEW JERSEY SOUND AMPLIFIER Application filed April 2, 1923. Serial No. 266,797.

This invention relates to means to amplify and propagate sound waves, particularly waves of the character transmitted by a diaphragm actuated by undulations induced in 5 an electric current, as in a sound reproducing device, and particularly adapted for use in connection with radio receiving apparatus, yand it is the obj ect of the invention to provide a sound amplifier of this character, which is l0 novel, compact and cheap in structure, and

highly eiiicient in propagating and magnifying the sound waves of dominant and un- -dertones In carrying out the invention l provide a 15 resonance chainber having walls adapted to vibrate by and in consonance with sound waves transmitted thereinto, said chamber being in the nature of a horn substantially of truncated pyramidal form with the sound '20 emitting opening at the larger end and a sound receiving opening at the smaller end, said chamber being formed of panels, preferably of relatively thin wood having alternate n hard and soft or spongy growth rings and X5 quarter sawed wherein the grain will entend in parallel and alternate hard and soft layers, with the panels supported at the edge portions practically without stress or strain, said horn with a sound receiving and transmitting chamber in communication with the sound receiving opening thereof being mounted in a casing or cabinet having an open side with the walls of the horn and cabinet in spaced relation and with the sound emitting opening of the horn arranged at and to conform to the contour of the open side of the cabinet.

In the drawing accompanying and form ing a part of this specification, Figure 1 is a perspective view of my improved sound am'- pliiier with a portion of the cabinet broken away to show the arrangement of the resonance and sound receiving chamber therein.

Figure 2 is a plan view with the cabinet in Y section.

Figure 3 is a front elevation with a portion of the wall of the resonance chamber broken away.

Figure t is a perspective view of the resonance chamber and connected sound receiving and transmitting chamber, partly broken away to show the connection of said chambers; and n Figure 5 is an enlarged fragmentary view in perspective to show the manner of supporting the panels at the edge portions with out stress or strain.

ln the embodying of the invention illus- 'trated in the drawing there is provided a cabinet or casing of rectangular shape and open at one side to constitute the front, as at i", and having a resonance chamber or horn arranged therein with the wall thereof in spaced relation to the wall of the cabinet to provide an air space between the two to permit of free vibratory movement of the wall of the reso nance chamber.

The resonance chamber is in the form of a truncated pyramid constructed and arranged of a plurality of triangular shaped panels, in the present instance four in number, 8, 9, 'l0 and il, preferably of wood, such as spruce, having alternate layers of hard and soft or spongy growth rings and quarter sawed. These panels are connected and supported at the longitudinal edge portions practically without stress or strain by engaging the side edge portions in grooves, as shown at 12, eirtending longitudinally of ribs 13 and secured therein by a yielding gum or cement. The panels are so constructed and arranged that the edge portions about the larger or sound emitting opening are at and conform to the contour of the open side or front of the cabinet, with one corner, as 9a, formed by a connection of one edge of panels 8 and 9 entend ing at a right angle to the open end of the horn and parallel to the corner le of the cabinet formed b fv a side 6a and the bottom of the cabinet and in a direction toward the corner formed by said side (ia and bottom 6b and the bacli wall 6C to a point where it meets a chamber l5 forming part of a sound. wave receiving and transmitting passage or chamber to be hereinafter described. The panel 8 en tends in parallel and spaced relation to the side 6a of the cabinet with the front edge portion extending from the top to the bottoni and the top edge inclined downward toward the back of the cabinet, as shown at 8a. The panel extends in parallel and spaced relation to the bottom 6b with the front edge marginal portion extending to the adjacent opposite side Wall oit the cabinet, and the edge of said panel at Which it is joined to the edOe portion or panel 10 through the rib 13 to 'lorm a corner 1OfL inclininc in a direction to Ward the side (3a and. back o1" the cabinet to the connection with the chamber 15. rlhe panel 10 extends perpendicular to the panel 9 and conif'erfres in a direction toward the panel 8 to a point Where it merges with the chamber 15. The top edge oit said panel 10 inclines downward at the same angle as the top edge oi;l panel 8. The juncture oi panel 11 with panel 10 to form the corner 11a is suoli that said corner con verges in a direction toward the chamber 15. The panel 11 is ol' the saine iorm as the panel t) haring one edge formingI with panel 8 the corner 8a exten/ling parallel to the side (3a, While the opposite longitudinal edge with panel 10 forming `the corner 11rL inclines in a direction. toward the side 6a and bach of the cabinet 'from the opposite side thereof. By this rrangenient of the panels there is formed a resonance chamber substantiall;v oil pyramidal torni haringan outlet at the larger end and at the open side olt the cabinet7 said chamber also having a sound receiving opening, in the present instance through the smaller truncated end of the chamber Where it is connected with the chamber 1F.

The chamber 15 ot rectangular form in cross section, although it could be of other shape, and extends from adjacent the bottom of the cabinet toward the top thereof and has a portion 16 -Xtending adjacent to the top and parallel therewith and the back to Ward the opposite side of the cabinet Where a 'further portion 17 of said chamber or gassage extends al-ong said side toward the front of the cabinet with a sound reproducing element in communication therewith, shown in a general Wa;7 at 18, said element including a diaphragm adapted to be vibrated either mechanically or by undulations in an electric current to transmit and transform said undulations into audible sound Waves.l The chamber is in the form of a trumpet or horn, the portion 1'? having substantially the same cross sectional dimension :for the entire length thereof, While the portion 16 tapers or increases in cross sectional dimension from the juncture thereof with the portion 17 to the portion 15. The chamber portions are of integral and rigid structure With the portions 15, which latter portion carries the resonance chamber' formed by the panels 8, 9, 10 and 11 and whereby said parts are mounted and supported in the cabinet free of and spaced from the Walls of the cabinet, For this purpose the bottom Wall of the chamber 15 is of increased thickness or has 'a bloclC 19 element 18 vibrated,

, ically or mechanica lijf, the Waves tansmittec 'from said iaphiagm into through t chambers l, 1G and 15 and the connection "2O thereof Witl'i the resl ,ce chan'iber setting up a vibration of tee panels oli said chamber in consonance with the transmitted sound `waves or Vibrati( and by arranoing said walls ot quarter served nood l wing alternate hard and sott growth rings the dominant tones of such sound vibrations are inagniiied and the overtones absorbed.

ly the construction and. arrangement of a resonant chamber described, a chamber ol: relatively small size will function to not only7 greatly amplit;7 and propagate the sound Waves 'transmitted thcreto9 but will also emit sounds oli clear and natural tone due to the inagnili'ying ot' the dominant tones and the absorbing of the, undertones.

lil/Thilo 'l lere is illustrated and described a particular construction and arrangement ot' my improved sound amplilier7 as by con structing` the resonance cl unber of four panels it Will be obvious that a. greater or less number et panels maj; be utilized and come Within the scope ot the invention, the invention residing in the coiniecting and supporting ot the panels at the longitrulinal edge portions Without sti yss or strain and the mounri ot said chamber in a cabinet in spaced relation to the Walls thereof whereinY the Walls off' the chamber may have free vibration, and that variations ay be resorted to and produce this result w out de'iarting' from the scope et the inventor.

Having thus described my iii'ifention, l claim:

1M ln a sound amplifie" tangular shape open i Within said cabinet co acted ot' panels con nccted at the sido ed portion to 'form a chamber harina; a sound eri-ritt ng opening ci rectangulai shape to conform Ato and at the c t cabinet, and a pair ot panels :i cabinet et rectroni;` and a horn onen Yfront el rnc eidtending at a right uncle to each other and parallel to the bottoni a side oit the cabinet and the connection ot raid pair ot panels extending parallel to the corner the cabinet 'tori'ned by d side and bottom oit the cabinet, and. the connected edges ot 'the other panels inclining troni the 'trent toward 'the back ot the cal et and converging in a direction toward the corni-r termed by the one side and bottom of the cabin having a sound Wave receiving opening 'he terminus ot said conve; png corners an he corner of the panels arianged at a righ; angle.

2. ln a sound amplifier a ca liner el' rectangular shape open at the ont and a horn Within said cabinet const ructed oli panels conler? llt-

lfli

nected at the side edge portions to form a chamber having a sound emitting opening of rectangular shape at and conforming to the open front of the cabinet, one pair of panels extending parallel to the bottom and a side of the cabinet and at a right angle to the corner formed by the panels and said corner extending parallel to the corner formed by said side and bottom of the cabinet, and the corners formed by the connections of the other panels converging in a direction toward the right angle corner formed by the one pair ot panels and in a direction toward the corner of the cabinet formed by the one side, bottom and back toward whichsaid latter corner of the horn entends, and said horn having a sound wave receiving opening.

3. In a sound amplifier as claimed in claim l, means to support the horn at its truncated end by the cabinet with the horn panels free et the Walls of the cabinet.

fl. In a sound ampliier as claimed in claim l, an elongated seund wave receiving and transmitting passage arranged within the cabinet and connected to the sound wave receiving opening of the horn.

5. In a sound amplitier as claimed in claim l, a sound Wave receiving and transmitting passage connected with the receiving opening of the horn, said passage extending from the corner oit the cabinet toward which the horn panels extend and upward along one side toward the top of the cabinet, along the corner formed by the juncture o the top and back of the cabinet to the opposite side and then along said side toward the front of the cabinet.

6. A sound amplitier as claimed in claim l, wherein the panels ot the horn are connected one with the other Without stress or strain and supported in the cabinet with the horn panels free of the walls oit the cabinet.

7. In a sound amplilier, a series of panels and grooved ribs interposed between them and in the grooves ot which ribs edge portions et the panels are engaged to connect and support the panels without stress or strain, said panels and ribs being constructed and arranged to form a horn substantially of rece tangle-pyramidal shape and having a sound receiving opening at the smaller end.

8. In sound amplifier as claimed in claim 7, cabinet having an open side in which the horn is mounted with the outlet opening at the open front of' the cabinet and with the marginal portion of the horn outlet arranged to conform to the contour of and in spaced relation to the opening in the front of the cabinet.

9. In a sound amplifier as claimed in claim an elongated sound receiving and trans mitting chamber connected to the sound receiving opening ot the horn, a cabinet having an open front and means to mount the chamber and horn in the cabinet with the outlet of the horn at and arranged to conform to the contour of and spaced from the opening in the front of the cabinet and with the walls of the horn tree of and in spaced relation to the walls of the cabinet.

10. In a sound amplifier, a horn of pyramidal form constructed of triangular panels of quarter sawed wood having alternate layers ot soft and hard growthl rings and connected at the longitudinal edge portions arranging the horn with an outlet at the larger end oi' rectangular form, two of said panels being connected to extend at a right angle, and the other panels connected to incline from the Open end in a direction toward the panel opposed thereto, and the corner formed by the juncture of said panels converging from the open end in a direction toward the right anole corner formed by the first two panels.

igned at New York city, in the county of yNew York and State of New York, this 31st .ay of March, A. D. 1928.

THEOPI'IILUS G. WILLIAMS. 

